ISL6612B, ISL6613B ® Data Sheet July 27, 2006 Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP The ISL6612B and ISL6613B are high frequency MOSFET drivers specifically designed to drive upper and lower power N-Channel MOSFETs in a synchronous rectified buck converter topology. These drivers combined with HIP63xx or ISL65xx Multi-Phase Buck PWM controllers and N-Channel MOSFETs form complete core-voltage regulator solutions for advanced microprocessors. The ISL6612B drives the upper gate to above rising VCC POR (7V), while the lower gate can be independently driven over a range from 5V to 12V. The ISL6613B drives both upper and lower gates over a range of 5V to 12V. This drivevoltage provides the flexibility necessary to optimize applications involving trade-offs between gate charge and conduction losses. These drivers are optimized for POL DC/DC Converters for IBA Systems. FN9205.3 Features • Pin-to-pin Compatible with HIP6601 SOIC family • Dual MOSFET Drives for Synchronous Rectified Bridge • Low VCC Rising Threshold (7V) for IBA Applications. • Advanced Adaptive Zero Shoot-Through Protection - Body Diode Detection - Auto-zero of rDS(ON) Conduction Offset Effect • Adjustable Gate Voltage (5V to 12V) for Optimal Efficiency • 36V Internal Bootstrap Schottky Diode • Bootstrap Capacitor Overcharging Prevention • Supports High Switching Frequency (up to 2MHz) - 3A Sinking Current Capability - Fast Rise/Fall Times and Low Propagation Delays • Three-State PWM Input for Output Stage Shutdown An advanced adaptive zero shoot-through protection is integrated to prevent both the upper and lower MOSFETs from conducting simultaneously and to minimize the dead time. These products add an overvoltage protection feature operational before VCC exceeds its turn-on threshold, at which the PHASE node is connected to the gate of the low side MOSFET (LGATE). The output voltage of the converter is then limited by the threshold of the low side MOSFET, which provides some protection to the microprocessor if the upper MOSFET(s) is shorted during initial start-up. • Three-State PWM Input Hysteresis for Applications With Power Sequencing Requirement These drivers also feature a three-state PWM input which, working together with Intersil’s multi-phase PWM controllers, prevents a negative transient on the output voltage when the output is shut down. This feature eliminates the Schottky diode that is used in some systems for protecting the load from reversed output voltage events. • Pb-Free Plus Anneal Available (RoHS Compliant) • Pre-POR Overvoltage Protection • VCC Undervoltage Protection • Expandable Bottom Copper Pad for Enhanced Heat Sinking • Dual Flat No-Lead (DFN) Package - Near Chip-Scale Package Footprint; Improves PCB Efficiency and Thinner in Profile Applications • Optimized for POL DC/DC Converters for IBA Systems • Core Regulators for Intel® and AMD® Microprocessors • High Current DC/DC Converters • High Frequency and High Efficiency VRM and VRD Related Literature • Technical Brief TB363 “Guidelines for Handling and Processing Moisture Sensitive Surface Mount Devices (SMDs)” • Technical Brief TB417 for Power Train Design, Layout Guidelines, and Feedback Compensation Design 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005-2006. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL6612B, ISL6613B Ordering Information PART NUMBER PART MARKING ISL6612BCB 6612BCB ISL6612BCB-T 6612BCB ISL6612BCBZ (Note) 6612BCBZ TEMP. RANGE (°C) 0 to 85 8 Ld SOIC M8.15 8 Ld SOIC (Pb-free) M8.15 8 Ld SOIC Tape and Reel 0 to 85 ISL6612BCBZ-T (Note) 6612BCBZ ISL6612BCR 12BC 0 to 85 ISL6612BCR-T 12BC 10 Ld 3x3 DFN Tape and Reel ISL6612BCRZ (Note) 12BZ 0 to 85 ISL6612BCRZ-T (Note) 12BZ ISL6612BECB 6612BECB 0 to 85 ISL6612BECB-T 6612BECB 8 Ld EPSOIC Tape and Reel ISL6612BECBZ (Note) 6612BECBZ ISL6612BECBZ-T (Note) 6612BECBZ ISL6612BEIB 6612BEIB -40°C to 85°C ISL6612BEIB-T 6612BEIB 8 Ld EPSOIC Tape and Reel ISL6612BEIBZ (Note) 6612BEIBZ -40°C to 85°C ISL6612BEIBZ-T (Note) 6612BEIBZ ISL6612BIB 6612BIB ISL6612BIB-T 6612BIB ISL6612BIBZ (Note) 6612BIBZ 8 Ld SOIC Tape and Reel (Pb-free) 10 Ld 3x3 DFN L10.3x3 10 Ld 3x3 DFN (Pb-free) L10.3x3 10 Ld 3x3 DFN Tape and Reel (Pb-free) 0 to 85 8 Ld EPSOIC M8.15B 8 Ld EPSOIC (Pb-free) M8.15B 8 Ld EPSOIC Tape and Reel (Pb-free) 8 Ld EPSOIC M8.15B 8 Ld EPSOIC (Pb-free) M8.15B 8 Ld EPSOIC Tape and Reel (Pb-free) -40°C to 85°C 8 Ld SOIC M8.15 8 Ld SOIC (Pb-free) M8.15 8 Ld SOIC Tape and Reel -40°C to 85°C ISL6612BIBZ-T (Note) 6612BIBZ ISL6612BIR 12BI -40°C to 85°C ISL6612BIR-T 12BI 10 Ld 3x3 DFN Tape and Reel ISL6612BIRZ (Note) 2BIZ -40°C to 85°C ISL6612BIRZ-T (Note) 2BIZ ISL6613BCB 6613BCB ISL6613BCB-T 6613BCB ISL6613BCBZ (Note) 6613BCBZ ISL6613BCBZ-T (Note) 6613BCBZ ISL6613BCR 13BC 0 to 85 ISL6613BCR-T 13BC 10 Ld 3x3 DFN Tape and Reel ISL6613BCRZ (Note) 13BZ 0 to 85 ISL6613BCRZ-T (Note) 13BZ ISL6613BECB 6613BECB 0 to 85 ISL6613BECB-T 6613BECB 8 Ld EPSOIC Tape and Reel ISL6613BECBZ (Note) 6613BECBZ ISL6613BECBZ-T (Note) 6613BECBZ ISL6613BEIB 6613BEIB -40°C to 85°C ISL6613BEIB-T 6613BEIB 8 Ld EPSOIC Tape and Reel ISL6613BEIBZ (Note) 6613BEIBZ -40°C to 85°C ISL6613BEIBZ-T (Note) 6613BEIBZ 2 PKG. DWG. # PACKAGE 8 Ld SOIC Tape and Reel (Pb-free) 10 Ld 3x3 DFN L10.3x3 10 Ld 3x3 DFN (Pb-free) L10.3x3 10 Ld 3x3 DFN Tape and Reel (Pb-free) 0 to 85 8 Ld SOIC M8.15 8 Ld SOIC (Pb-free) M8.15 8 Ld SOIC Tape and Reel 0 to 85 8 Ld SOIC Tape and Reel (Pb-free) 10 Ld 3x3 DFN L10.3x3 10 Ld 3x3 DFN (Pb-free) L10.3x3 10 Ld 3x3 DFN Tape and Reel (Pb-free) 0 to 85 8 Ld EPSOIC M8.15B 8 Ld EPSOIC (Pb-free) M8.15B 8 Ld EPSOIC Tape and Reel (Pb-free) 8 Ld EPSOIC M8.15B 8 Ld EPSOIC (Pb-free) M8.15B 8 Ld EPSOIC Tape and Reel (Pb-free) FN9205.3 July 27, 2006 ISL6612B, ISL6613B Ordering Information (Continued) PART NUMBER PART MARKING ISL6613BIB 6613BIB ISL6613BIB-T 6613BIB ISL6613BIBZ (Note) 6613BIBZ TEMP. RANGE (°C) PKG. DWG. # PACKAGE -40°C to 85°C 8 Ld SOIC M8.15 8 Ld SOIC (Pb-free) M8.15 8 Ld SOIC Tape and Reel -40°C to 85°C ISL6613BIBZ-T (Note) 6613BIBZ ISL6613BIR 13BI 8 Ld SOIC Tape and Reel (Pb-free) -40°C to 85°C ISL6613BIR-T 13BI 10 Ld 3x3 DFN Tape and Reel ISL6613BIRZ (Note) 3BIZ -40°C to 85°C ISL6613BIRZ-T (Note) 3BIZ 10 Ld 3x3 DFN L10.3x3 10 Ld 3x3 DFN (Pb-free) L10.3x3 10 Ld 3x3 DFN Tape and Reel (Pb-free) NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. Contact the factory for availability. Pinouts ISL6612BCB, ISL6613BCB (SOIC) ISL6612BECB, ISL6613BECB (EPSOIC) TOP VIEW UGATE 1 8 PHASE BOOT 2 7 PVCC PWM 3 6 VCC GND 4 5 LGATE GND ISL6612BCR, ISL6613BCR (10L 3x3 DFN) TOP VIEW 1 UGATE BOOT 2 N/C 3 PWM 4 GND 5 10 PHASE 9 PVCC GND 8 N/C 7 VCC 6 LGATE Block Diagram ISL6612B AND ISL6613B UVCC BOOT VCC UGATE PRE-POR OVP FEATURES +5V 10K POR/ PWM SHOOTTHROUGH PROTECTION PHASE (LVCC) PVCC UVCC = VCC FOR ISL6612B UVCC = PVCC FOR ISL6613B CONTROL 8K LOGIC LGATE GND PAD 3 FOR DFN AND EPSOIC-DEVICES, THE PAD ON THE BOTTOM SIDE OF THE PACKAGE MUST BE SOLDERED TO THE CIRCUIT’S GROUND. FN9205.3 July 27, 2006 ISL6612B, ISL6613B Typical Application - 3 Channel Converter Using ISL65xx and ISL6612B Gate Drivers +7V to +12V +5V TO 12V VCC BOOT UGATE PVCC PWM ISL6612B PHASE LGATE GND +7V to +12V +5V TO 12V +5V VCC VFB VCC UGATE PVCC PWM1 VSEN PWM2 PGOOD +VCORE BOOT COMP PWM ISL6612B PHASE PWM3 LGATE MAIN CONTROL ISL65xx VID GND ISEN1 ISEN2 FS ISEN3 +7V to +12V +5V TO 12V GND VCC BOOT UGATE PVCC ISL6612B PHASE PWM LGATE GND 4 FN9205.3 July 27, 2006 ISL6612B, ISL6613B Absolute Maximum Ratings Thermal Information Supply Voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15V Supply Voltage (PVCC) . . . . . . . . . . . . . . . . . . . . . . . . . VCC + 0.3V BOOT Voltage (VBOOT-GND). . . . . . . . . . . . . . . . . . . . . . . . . . . .36V Input Voltage (VPWM) . . . . . . . . . . . . . . . . . . . . . . GND - 0.3V to 7V UGATE. . . . . . . . . . . . . . . . . . . VPHASE - 0.3VDC to VBOOT + 0.3V VPHASE - 3.5V (<100ns Pulse Width, 2µJ) to VBOOT + 0.3V LGATE . . . . . . . . . . . . . . . . . . . . . . GND - 0.3VDC to VPVCC + 0.3V GND - 5V (<100ns Pulse Width, 2µJ) to VPVCC + 0.3V PHASE. . . . . . . . . . . . . . . . . . . . . . . . . . . . GND - 0.3VDC to 15VDC GND - 8V (<400ns, 20µJ) to 30V (<200ns, VBOOT-GND<36V) ESD Rating Human Body Model . . . . . . . . . . . . . . . . . . . . Class I JEDEC STD Thermal Resistance θJA (°C/W) θJC (°C/W) SOIC Package (Note 1) . . . . . . . . . . . . 100 N/A EPSOIC Package (Notes 2, 3). . . . . . . 50 7 DFN Package (Notes 2, 3) . . . . . . . . . . 48 7 Maximum Junction Temperature (Plastic Package) . . . . . . . . 150°C Maximum Storage Temperature Range . . . . . . . . . . . -65°C to 150°C Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300°C (SOIC - Lead Tips Only) Recommended Operating Conditions Ambient Temperature Range . . . . . . . . . . . . . . . . . . . .-40°C to 85°C Maximum Operating Junction Temperature . . . . . . . . . . . . . . 125°C Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V to 13.2V Supply Voltage Range, PVCC . . . . . . . . . . . . . . . . 5V to 12V ±10% CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. NOTES: 1. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. 2. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech Brief TB379. 3. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside. Electrical Specifications Recommended Operating Conditions, Unless Otherwise Noted. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNITS IVCC ISL6612B, fPWM = 300kHz, VVCC =12V - 8 - mA ISL6613B, fPWM = 300kHz, VVCC =12V - 4.5 - mA ISL6612B, fPWM = 1MHz, VVCC = 12V - 10.5 - mA ISL6613B, fPWM = 1MHz, VVCC = 12V - 5 - mA VCC SUPPLY CURRENT Bias Supply Current IVCC Gate Drive Bias Current IPVCC IPVCC ISL6612B, fPWM=300kHz, VPVCC=12V - 4 - mA ISL6613B, fPWM=300kHz, VPVCC=12V - 7.5 - mA ISL6612B, fPWM = 1MHz, VPVCC = 12V - 5 - mA ISL6613B, fPWM = 1MHz, VPVCC = 12V - 8.5 - mA 6.92 7.10 V 7.10 V 5.60 V 5.60 V POWER-ON RESET AND ENABLE VCC Rising Threshold 0°C to 85°C 6.75 VCC Rising Threshold -40°C to 85°C 5.75 VCC Falling Threshold 0°C to 85°C 5.20 VCC Falling Threshold -40°C to 85°C 4.20 5.44 PWM INPUT (See Timing Diagram on Page 7) VPWM = 5V - 500 - µA VPWM = 0V - -450 - µA PWM Rising Threshold VCC = 12V - 3.00 - V PWM Falling Threshold VCC = 12V - 2.00 - V Typical Three-State Shutdown Window VCC = 12V 1.80 2.40 V Three-State Lower Gate Falling Threshold VCC = 12V 1.50 V Three-State Lower Gate Rising Threshold VCC = 12V 1.00 V Input Current IPWM 5 FN9205.3 July 27, 2006 ISL6612B, ISL6613B Electrical Specifications Recommended Operating Conditions, Unless Otherwise Noted. (Continued) PARAMETER SYMBOL Three-State Upper Gate Rising Threshold MIN VCC = 12V Three-State Upper Gate Falling Threshold Shutdown Holdoff Time TEST CONDITIONS TYP MAX 3.20 VCC = 12V V 2.60 tTSSHD UNITS V - 245 - ns UGATE Rise Time tRU VPVCC = 12V, 3nF Load, 10% to 90% - 26 - ns LGATE Rise Time tRL VPVCC = 12V, 3nF Load, 10% to 90% - 18 - ns UGATE Fall Time tFU VPVCC = 12V, 3nF Load, 90% to 10% - 18 - ns LGATE Fall Time tFL VPVCC = 12V, 3nF Load, 90% to 10% - 12 - ns UGATE Turn-On Propagation Delay (Note 4) tPDHU VPVCC = 12V, 3nF Load, Adaptive - 10 - ns LGATE Turn-On Propagation Delay (Note 4) tPDHL VPVCC = 12V, 3nF Load, Adaptive - 10 - ns UGATE Turn-Off Propagation Delay (Note 4) tPDLU VPVCC = 12V, 3nF Load - 10 - ns LGATE Turn-Off Propagation Delay (Note 4) tPDLL VPVCC = 12V, 3nF Load - 10 - ns LG/UG Three-State Propagation Delay (Note 4) tPDTS VPVCC = 12V, 3nF Load - 10 - ns Upper Drive Source Current IU_SOURCE VPVCC = 12V, 3nF Load - 1.25 - Α Upper Drive Source Impedance RU_SOURCE 150mA Source Current 1.25 2.0 3.0 Ω OUTPUT (Note 4) Upper Drive Sink Current IU_SINK VPVCC = 12V, 3nF Load - 2 - Α Upper Drive DC Sink Impedance RU_SINK 150mA Source Current .9 1.6 3.0 Ω Lower Drive Source Current IL_SOURCE VPVCC = 12V, 3nF Load Lower Drive Source Impedance RL_SOURCE 150mA Source Current Lower Drive Sink Current IL_SINK VPVCC = 12V, 3nF Load Lower Drive Sink Impedance RL_SINK 150mA Sink Current - 2 - A 0.85 1.35 2.2 Ω - 3 - A 0.60 0.80 1.35 Ω NOTE: 4. Guaranteed by design. Not 100% tested in production. Functional Pin Description PACKAGE PIN # SOIC DFN PIN SYMBOL 1 1 UGATE Upper gate drive output. Connect to gate of high-side power N-Channel MOSFET. 2 2 BOOT Floating bootstrap supply pin for the upper gate drive. Connect the bootstrap capacitor between this pin and the PHASE pin. The bootstrap capacitor provides the charge to turn on the upper MOSFET. See the Internal Bootstrap Device section under DESCRIPTION for guidance in choosing the capacitor value. - 3, 8 N/C 3 4 PWM The PWM signal is the control input for the driver. The PWM signal can enter three distinct states during operation, see the three-state PWM Input section under DESCRIPTION for further details. Connect this pin to the PWM output of the controller. 4 5 GND Bias and reference ground. All signals are referenced to this node. It is also the power ground return of the driver. 5 6 LGATE 6 7 VCC 7 9 PVCC This pin supplies power to both upper and lower gate drives in ISL6613B; only the lower gate drive in ISL6612B. Its operating range is +5V to 12V. Place a high quality low ESR ceramic capacitor from this pin to GND. 8 10 PHASE Connect this pin to the SOURCE of the upper MOSFET and the DRAIN of the lower MOSFET. This pin provides a return path for the upper gate drive. 9 11 PAD FUNCTION No Connection. Lower gate drive output. Connect to gate of the low-side power N-Channel MOSFET. Connect this pin to a +12V bias supply. Place a high quality low ESR ceramic capacitor from this pin to GND. Connect this pad to the power ground plane (GND) via thermally enhanced connection. 6 FN9205.3 July 27, 2006 ISL6612B, ISL6613B Description 1.5V<PWM<3.2V 1.0V<PWM<2.6V PWM tPDLU tPDHU tTSSHD tPDTS tPDTS UGATE tFU tRU LGATE tFL tRL tTSSHD tPDLL tPDHL FIGURE 1. TIMING DIAGRAM Operation Designed for versatility and speed, the ISL6612B and ISL6613B MOSFET drivers control both high-side and low-side N-Channel FETs of a half-bridge power train from one externally provided PWM signal. Prior to VCC exceeding its POR level, the Pre-POR overvoltage protection function is activated during initial start-up; the upper gate (UGATE) is held low and the lower gate (LGATE), controlled by the Pre-POR overvoltage protection circuits, is connected to the PHASE. Once the VCC voltage surpasses the VCC Rising Threshold (See Electrical Specifications), the PWM signal takes control of gate transitions. A rising edge on PWM initiates the turn-off of the lower MOSFET (see Timing Diagram). After a short propagation delay [tPDLL], the lower gate begins to fall. Typical fall times [tFL] are provided in the Electrical Specifications section. Adaptive shoot-through circuitry monitors the PHASE voltage and determines the upper gate delay time [tPDHU]. This prevents both the lower and upper MOSFETs from conducting simultaneously. Once this delay period is complete, the upper gate drive begins to rise [tRU] and the upper MOSFET turns on. A falling transition on PWM results in the turn-off of the upper MOSFET and the turn-on of the lower MOSFET. A short propagation delay [tPDLU] is encountered before the upper gate begins to fall [tFU]. Again, the adaptive shoot-through circuitry determines the lower gate delay time, tPDHL. The PHASE voltage and the UGATE voltage are monitored, and the lower gate is allowed to rise after PHASE drops below a level or the voltage of UGATE to PHASE reaches a level depending upon the current direction (See next section for details). The lower gate then rises [tRL], turning on the lower MOSFET. thresholds outlined in the ELECTRICAL SPECIFICATIONS 7 Advanced Adaptive Zero Shoot-Through Deadtime Control (Patent Pending) These drivers incorporate a unique adaptive deadtime control technique to minimize deadtime, resulting in high efficiency from the reduced freewheeling time of the lower MOSFETs’ body-diode conduction, and to prevent the upper and lower MOSFETs from conducting simultaneously. This is accomplished by ensuring either rising gate turns on its MOSFET with minimum and sufficient delay after the other has turned off. During turn-off of the lower MOSFET, the PHASE voltage is monitored until it reaches a -0.2V/+0.8V trip point for a forward/reverse current, at which time the UGATE is released to rise. An auto-zero comparator is used to correct the rDS(ON) drop in the phase voltage preventing from false detection of the -0.2V phase level during rDS(ON conduction period. In the case of zero current, the UGATE is released after 35ns delay of the LGATE dropping below 0.5V. During the phase detection, the disturbance of LGATE’s falling transition on the PHASE node is blanked out to prevent falsely tripping. Once the PHASE is high, the advanced adaptive shoot-through circuitry monitors the PHASE and UGATE voltages during a PWM falling edge and the subsequent UGATE turn-off. If either the UGATE falls to less than 1.75V above the PHASE or the PHASE falls to less than +0.8V, the LGATE is released to turn on. Three-State PWM Input A unique feature of these drivers and other Intersil drivers is the addition of a shutdown window to the PWM input. If the PWM signal enters and remains within the shutdown window for a set holdoff time, the driver outputs are disabled and both MOSFET gates are pulled and held low. The shutdown state is removed when the PWM signal moves outside the shutdown window. Otherwise, the PWM rising and falling determine when the lower and upper gates are enabled. FN9205.3 July 27, 2006 ISL6612B, ISL6613B This feature helps prevent a negative transient on the output voltage when the output is shut down, eliminating the Schottky diode that is used in some systems for protecting the load from reversed output voltage events. In addition, more than 400mV hysteresis also incorporates into the three-state shutdown window to eliminate PWM input oscillations due to the capacitive load seen by the PWM input through the body diode of the controller’s PWM output when the power-up and/or power-down sequence of bias supplies of the driver and PWM controller are required. As an example, suppose two IRLR7821 FETs are chosen as the upper MOSFETs. The gate charge, QG, from the data sheet is 10nC at 4.5V (VGS) gate-source voltage. Then the QGATE is calculated to be 53nC for UVCC (i.e. PVCC in ISL6613B, VCC in ISL6612B) =12V. We will assume a 200mV droop in drive voltage over the PWM cycle. We find that a bootstrap capacitance of at least 0.267µF is required. 1.6 1.4 Power-On Reset (POR) Function CBOOT_CAP (µF) 1.2 During initial start-up, the VCC voltage rise is monitored. Once the rising VCC voltage exceeds 6.9V (typically), operation of the driver is enabled and the PWM input signal takes control of the gate drives. If VCC drops below the falling threshold of 5.6V (typically), operation of the driver is disabled. 1. 0.8 0.6 QGATE = 100nC 0.4 Pre-POR Overvoltage Protection 50nC Prior to VCC exceeding its POR level, the upper gate is held low and the lower gate is controlled by the overvoltage protection circuits during initial startup. The PHASE is connected to the gate of the low side MOSFET (LGATE), which provides some protection to the microprocessor if the upper MOSFET(s) is shorted during initial start-up. For complete protection, the low side MOSFET should have a gate threshold well below the maximum voltage rating of the load/microprocessor. When VCC drops below its POR level, both gates pull low and the Pre-POR overvoltage protection circuits are not activated until VCC resets. Internal Bootstrap Device Both drivers feature an internal bootstrap schottky diode. Simply adding an external capacitor across the BOOT and PHASE pins completes the bootstrap circuit. The bootstrap function is also designed to prevent the bootstrap capacitor from overcharging due to the large negative swing at the trailing-edge of the PHASE node. This reduces voltage stress on the boot to phase pins. The bootstrap capacitor must have a maximum voltage rating above UVCC + 5V and its capacitance value can be chosen from the following equation: Q GATE C BOOT_CAP ≥ -------------------------------------∆V BOOT_CAP (EQ. 1) Q G1 • UVCC Q GATE = ------------------------------------ • N Q1 V GS1 where QG1 is the amount of gate charge per upper MOSFET at VGS1 gate-source voltage and NQ1 is the number of control MOSFETs. The ∆VBOOT_CAP term is defined as the allowable droop in the rail of the upper gate drive. 8 0.2 20nC 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 ∆VBOOT_CAP (V) FIGURE 2. BOOTSTRAP CAPACITANCE vs BOOT RIPPLE VOLTAGE Gate Drive Voltage Versatility The ISL6612B and ISL6613B provide the user flexibility in choosing the gate drive voltage for efficiency optimization. The ISL6612B upper gate drive can be driven above VCC rising POR (7V) to 12V, but the lower drive rail can range from 12V down to 5V depending on what voltage is applied to PVCC. The ISL6613B ties the upper and lower drive rails together. Simply applying a voltage from 5V up to 12V on PVCC sets both gate drive rail voltages simultaneously. Power Dissipation Package power dissipation is mainly a function of the switching frequency (FSW), the output drive impedance, the external gate resistance, and the selected MOSFET’s internal gate resistance and total gate charge. Calculating the power dissipation in the driver for a desired application is critical to ensure safe operation. Exceeding the maximum allowable power dissipation level will push the IC beyond the maximum recommended operating junction temperature of 125°C. The maximum allowable IC power dissipation for the SO8 package is approximately 800mW at room temperature, while the power dissipation capacity in the EPSOIC and DFN packages, with an exposed heat escape pad, is more than 2W and 1.5W, respectively. Both EPSOIC and DFN packages are more suitable for high frequency applications. See Layout Considerations paragraph for thermal transfer improvement suggestions. When designing the driver into an application, it is recommended that the following calculation is used to ensure safe operation at the desired frequency for FN9205.3 July 27, 2006 ISL6612B, ISL6613B the selected MOSFETs. The total gate drive power losses due to the gate charge of MOSFETs and the driver’s internal circuitry and their corresponding average driver current can be estimated with EQs. 2 and 3, respectively, BOOT UVCC D CGD RHI1 P Qg_TOT = P Qg_Q1 + P Qg_Q2 + I Q • VCC G CDS (EQ. 2) RLO1 Q G1 • UVCC 2 P Qg_Q1 = --------------------------------------- • F SW • N Q1 V GS1 RG1 RGI1 CGS Q1 S Q G2 • LVCC 2 P Qg_Q2 = -------------------------------------- • F SW • N Q2 V GS2 PHASE FIGURE 3. TYPICAL UPPER-GATE DRIVE TURN-ON PATH ⎛ Q G1 • UVCC • NQ1 Q G2 • LVCC • N Q2⎞ I DR = ⎜ ----------------------------------------------------- + -----------------------------------------------------⎟ • F SW + I Q V GS1 V GS2 ⎝ ⎠ LVCC (EQ. 3) where the gate charge (QG1 and QG2) is defined at a particular gate to source voltage (VGS1and VGS2) in the corresponding MOSFET datasheet; IQ is the driver’s total quiescent current with no load at both drive outputs; NQ1 and NQ2 are the number of upper and lower MOSFETs, respectively; UVCC and LVCC are the drive voltages for both upper and lower FETs, respectively. The IQ*VCC product is the quiescent power of the driver without capacitive load and is typically 116mW at 300kHz. The total gate drive power losses are dissipated among the resistive components along the transition path. The drive resistance dissipates a portion of the total gate drive power losses, the rest will be dissipated by the external gate resistors (RG1 and RG2) and the internal gate resistors (RGI1 and RGI2) of MOSFETs. Figures 3 and 4 show the typical upper and lower gate drives turn-on transition path. The power dissipation on the driver can be roughly estimated as: P DR = P DR_UP + P DR_LOW + I Q • VCC (EQ. 4) R LO1 R HI1 ⎛ ⎞ P Qg_Q1 P DR_UP = ⎜ -------------------------------------+ ---------------------------------------⎟ • --------------------2 R + R R + R ⎝ HI1 EXT1 LO1 EXT1⎠ R LO2 R HI2 ⎛ ⎞ P Qg_Q2 P DR_LOW = ⎜ -------------------------------------+ ---------------------------------------⎟ • --------------------2 ⎝ R HI2 + R EXT2 R LO2 + R EXT2⎠ R GI1 R EXT1 = R G1 + ------------N Q1 R GI2 R EXT2 = R G2 + ------------N Q2 9 D CGD RHI2 RLO2 G RG2 CDS RGI2 CGS Q2 S FIGURE 4. TYPICAL LOWER-GATE DRIVE TURN-ON PATH Layout Considerations For heat spreading, place copper underneath the IC whether it has an exposed pad or not. The copper area can be extended beyond the bottom area of the IC and/or connected to buried copper plane(s) with thermal vias. This combination of vias for vertical heat escape, extended copper plane, and buried planes for heat spreading allows the IC to achieve its full thermal potential. Place each channel power component as close to each other as possible to reduce PCB copper losses and PCB parasitics: shortest distance between DRAINs of upper FETs and SOURCEs of lower FETs; shortest distance between DRAINs of lower FETs and the power ground. Thus, smaller amplitudes of positive and negative ringing are on the switching edges of the PHASE node. However, some space in between the power components is required for good airflow. The traces from the drivers to the FETs should be kept short and wide to reduce the inductance of the traces and to promote clean drive signals. FN9205.3 July 27, 2006 ISL6612B, ISL6613B Dual Flat No-Lead Plastic Package (DFN) 2X 0.15 C A D A L10.3x3 10 LEAD DUAL FLAT NO-LEAD PLASTIC PACKAGE MILLIMETERS 2X 0.15 C B SYMBOL MIN 6 INDEX AREA 0.80 0.90 1.00 - - - 0.05 - 0.28 5,8 2.05 7,8 1.65 7,8 0.20 REF 0.18 D 1.95 E 0.10 C 0.08 C SIDE VIEW C SEATING PLANE 1 e 1.60 - 0.50 BSC - k 0.25 - - L 0.30 0.35 0.40 N 10 Nd 5 3 3. Nd refers to the number of terminals on D. 4. All dimensions are in millimeters. Angles are in degrees. 5. Dimension b applies to the metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. E2/2 6. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature. NX L N-1 7. Dimensions D2 and E2 are for the exposed pads which provide improved electrical and thermal performance. NX b 5 (Nd-1)Xe REF. 8 2 2. N is the number of terminals. E2 e - 1. Dimensioning and tolerancing conform to ASME Y14.5-1994. NX k 8 1.55 NOTES: D2/2 2 N - Rev. 3 6/04 D2 (DATUM B) 2.00 8 7 6 INDEX AREA (DATUM A) A3 - 3.00 BSC E2 A 0.23 3.00 BSC D2 B NOTES A b TOP VIEW MAX A1 A3 E NOMINAL 0.10 M C A B 8. Nominal dimensions are provided to assist with PCB Land Pattern Design efforts, see Intersil Technical Brief TB389. BOTTOM VIEW C L 0.415 NX (b) (A1) 0.200 5 L NX L e SECTION "C-C" NX b C C C TERMINAL TIP FOR ODD TERMINAL/SIDE 10 FN9205.3 July 27, 2006 ISL6612B, ISL6613B Small Outline Exposed Pad Plastic Packages (EPSOIC) M8.15B N INDEX AREA H 0.25(0.010) M 8 LEAD NARROW BODY SMALL OUTLINE EXPOSED PAD PLASTIC PACKAGE B M E INCHES -B1 2 3 TOP VIEW L SEATING PLANE -A- h x 45o A D -C- A1 B 0.25(0.010) M C 0.10(0.004) C A M B S SIDE VIEW SYMBOL MIN MAX MIN MAX NOTES A 0.056 0.066 1.43 1.68 - A1 0.001 0.005 0.03 0.13 - B 0.0138 0.0192 0.35 0.49 9 C 0.0075 0.0098 0.19 0.25 - D 0.189 0.196 4.80 4.98 3 E 0.150 0.157 3.31 3.39 4 e α e MILLIMETERS 0.050 BSC 1.27 BSC - H 0.230 0.244 5.84 6.20 - h 0.010 0.016 0.25 0.41 5 L 0.016 0.035 0.41 0.64 6 N 8 8 7 α 0o 8o 0o 8o - P - 0.094 - 2.387 11 P1 - 0.094 - 2.387 11 Rev. 2 11/03 1 2 NOTES: 3 1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of Publication Number 95. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. P1 3. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. N 4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per side. P BOTTOM VIEW 5. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 6. “L” is the length of terminal for soldering to a substrate. 7. “N” is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value of 0.61mm (0.024 inch). 10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact. 11. Dimensions “P” and “P1” are thermal and/or electrical enhanced variations. Values shown are maximum size of exposed pad within lead count and body size. 11 FN9205.3 July 27, 2006 ISL6612B, ISL6613B Small Outline Plastic Packages (SOIC) M8.15 (JEDEC MS-012-AA ISSUE C) N INDEX AREA H 0.25(0.010) M 8 LEAD NARROW BODY SMALL OUTLINE PLASTIC PACKAGE B M E INCHES -B- 1 2 SYMBOL 3 L SEATING PLANE -A- h x 45o A D -C- α e A1 B 0.25(0.010) M C C A M B S 1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of Publication Number 95. MILLIMETERS MIN MAX NOTES A 0.0532 0.0688 1.35 1.75 - 0.0040 0.0098 0.10 0.25 - B 0.013 0.020 0.33 0.51 9 C 0.0075 0.0098 0.19 0.25 - D 0.1890 0.1968 4.80 5.00 3 E 0.1497 0.1574 3.80 4.00 4 0.050 BSC 1.27 BSC - H 0.2284 0.2440 5.80 6.20 - h 0.0099 0.0196 0.25 0.50 5 L 0.016 0.050 0.40 1.27 6 8o 0o N NOTES: MAX A1 e 0.10(0.004) MIN α 8 0o 8 7 8o Rev. 0 12/93 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. 4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per side. 5. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 6. “L” is the length of terminal for soldering to a substrate. 7. “N” is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value of 0.61mm (0.024 inch). 10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 12 FN9205.3 July 27, 2006